Structure in C


1. What is Structure in C ?

Ans: A Structure is a user-defined data type that allows you to group together variables of different data types under a single name, creating a composite data type to represent complex entities.

Syntax  : struct [Structure_name]

{

                 Datatype Var1;

                  Datatype Var2;

                  Datatype Var3;

               };

Simple Explanation :



In this image we can see that A group of Employees have given a task that they need to collect the data of all the employees in the company using c. The company contains 500 employees. It is not easy to take a single variable for a single employees. The structure in c is a container for all type of datatype. It contains various datatypes under a single variable. Which will make the employs work more easy.


1. Deceleration of structure.

We can declare the structure along with structure definition or separately.

ex:

    struct Student { // Structure declaration

        char name[50]; // Member (char array for name)

        int rollNumber; // Member (integer for roll number)

        float marks; // Member (float for marks)

    };


    int main() {

        struct Student s1; // Declare a structure variable

        return 0;

    }

2. Initialization of structure :

    struct Student { // Structure declaration

        char name[50]; // Member (char array for name)

        int rollNumber; // Member (integer for roll number)

        float marks; // Member (float for marks)

    };


    int main() {

        struct Student s1; // Declare a structure variable

        // Accessing members

        strcpy(s1.name, "Alice");

        s1.rollNumber = 101;

        s1.marks = 85.5;

        return 0;

    }

Note: The Dot used in s1.rollnumber is used to operate the member of structure Which is also known as structure member operator.

1. WAP a program to store a value of employes.


#include <stdio.h>
#include <string.h>

struct Employee {
    int id;
    char name[50];
    float salary;
    char department[50];
};

int main() {
    int numEmployees;


    printf("Enter the number of employees: ");
    scanf("%d", &numEmployees);


    struct Employee employees[numEmployees];

   
    for (int i = 0; i < numEmployees; i++) {
        printf("\nEnter details for employee %d:\n", i + 1);

        printf("ID: ");
        scanf("%d", &employees[i].id);

        printf("Name: ");
        scanf(" %s", employees[i].name); 

        printf("Salary: ");
        scanf("%f", &employees[i].salary);

        printf("Department: ");
        scanf(" %s", employees[i].department); 
    }

 
    printf("\n--- Employee Data ---\n");
    for (int i = 0; i < numEmployees; i++) {
        printf("Employee ID: %d\n", employees[i].id);
        printf("Name: %s\n", employees[i].name);
        printf("Salary: %.2f\n", employees[i].salary);
        printf("Department: %s\n", employees[i].department);
        printf("\n");
    }

    return 0;
}

Output :